- An unpaired anatomical structure.
- Not one of a pair, as a vein or muscle; occurring singly.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for azygos
The vertebral and segmental venous system, representing the azygos veins of the mammalia, is very rudimentary (Figs. 266 and 267).The Anatomy of the Human Peritoneum and Abdominal Cavity
George. S. Huntington
In Halmaturus bennettii there are two azygos veins, one left and one right, of which the left is rather the larger.
The Edentates, at any rate the American forms, have a double vena cava posterior and no azygos vein.
This discovery of a tuberculosis of the blood-vessels was confirmed by Klebs, who had found a tuberculosis of the azygos veins.